CN109367059A - A microwave curing device for composite materials - Google Patents

Abstract

The invention provides a microwave curing device for composite materials, comprising an electric heating element, a vibrating table, a microwave generator, a microwave cavity, a microwave partial shielding element and a vacuuming part, wherein the electric heating element and the vibrating table are both arranged in the microwave cavity; The stage is used for placing the composite material, the microwave generator sends microwaves into the microwave cavity for heating the composite material, the electric heating element is also used for heating the composite material, and the microwave partial shielding element Located in the microwave cavity and used to cover the outer surface of the composite material, the microwave partial shielding member is composed of a microwave shielding area and a microwave transmitting area; the vibration table is capable of providing the composite material with a vibration frequency below 5000 Hz. And a vibration table that can provide vibration with a vibration acceleration of more than 2g. The device of the present invention can cure the composite material under atmospheric pressure to obtain a product with excellent performance.

Description

A microwave curing device for composite materials

technical field

The invention belongs to the field of composite material curing and molding, and particularly relates to a microwave curing device for composite materials.

Background technique

At present, the molding of high-performance resin matrix composite materials for aerospace mainly uses the autoclave process, because it generally requires relatively high temperature and curing pressure to eliminate the bubbles generated by the resin matrix during the curing process, such as T800 carbon fiber reinforced epoxy resin The resin prepreg is cured at 180°C and 0.6MPa to avoid loose pores and poor mechanical properties inside the cured part.

In the traditional autoclave curing process, due to the differences in the geometric dimensions, material systems and curing process parameters of the composite parts, the internal temperature and curing degree of the parts will be unevenly distributed to varying degrees, resulting in complex internal parts. Stress, which seriously affects the co-manufacturing of composite parts, especially for solidified thick section parts, there is a large temperature gradient inside the part, so the complex internal stress will cause the part to delaminate and matrix cracking and other defects, and even the parts are damaged during molding.

Because microwave has the advantages of selective heating, fast heating, uniform heating, strong penetration, and low thermal inertia, the application of microwave technology in the field of composite material curing can significantly reduce curing time, reduce production costs, and obtain excellent product performance. , has huge development potential. For example, the patent rights CN201610025303, CN201610027791, CN201610027866, CN201610030557, and CN201710214268 previously obtained by the inventor of the present application all use the microwave combined with the autoclave process to heat-press and solidify the composite material. So that the hot-pressed cured composite parts can obtain the precise required temperature field during the curing process.

However, the above-mentioned composite material curing process is inseparable from the use of autoclave. The autoclave forming process has some disadvantages such as high price of the autoclave equipment itself, low production efficiency, high energy consumption, high equipment manufacturing and operating costs, and high requirements for forming molds. In addition, when the high-pressure operation in the autoclave is used in combination with the microwave, there are certain safety hazards. This has become a bottleneck restricting the wide application of composite materials, and low-cost non-autoclave forming technology was born under this background.

The non-autoclave forming technology is a low-cost composite material manufacturing technology. The main difference between it and the autoclave forming process is that no external pressure needs to be applied during forming. The expensive autoclave is abandoned, and only an oven and a vacuum system are used. , so the production cost of composite curing is low. This is superior to the autoclave process in terms of equipment molding and tooling costs. However, obtaining cured composite parts of the same quality as the autoclave process is the main goal of non-autoclave technology.

However, non-autoclave molded composite parts have higher porosity due to low molding pressures. Generally, the porosity of the main load-bearing structural parts of autoclaved aerospace should be less than 1%, and the porosity of the secondary load-bearing structural parts should be less than 2%. Technical curing, the porosity of its parts can be as high as 5% to 10%. Porosity is an important factor affecting the performance of composite materials, so reducing the porosity of the cured composite parts and making it reach the porosity level of the autoclave-cured composite parts has become a research topic in non-autoclave forming technology. The primary task.

That is to say, with the continuous development of the curing process of resin materials, some non-load-bearing components with little force have been produced by the external curing process of autoclave. However, for composite materials such as T800 carbon fiber reinforced epoxy resin prepreg used in aerospace, the curing pressure of vacuuming alone is far from enough. Because the curing pressure is not enough, defects such as voids will be formed inside the part after curing, which will greatly reduce the pressure of curing. Reduce the mechanical properties of parts. Therefore, for advanced resin-based carbon fiber reinforced composite materials used in aerospace, the use of the existing autoclave external curing technology can not meet the requirements.

Therefore, in order to save cost and improve the safety factor, when the composite material is cured under high pressure without the use of an autoclave, if the porosity of the high-performance composite material for aerospace can be achieved similar to that in the autoclave. effect, which is a problem to be solved by those skilled in the art. Therefore, those skilled in the art need to develop a corresponding device and method for curing high-performance resin-based carbon fiber reinforced composite parts.

SUMMARY OF THE INVENTION

Therefore, the present invention provides a microwave curing device for composite materials, which includes an electric heating element, a vibrating table, a microwave generator, a microwave cavity, a partial microwave shielding element and a vacuuming element, and the electric heating element and the vibrating table are both arranged in the microwave cavity. The vibrating table is used to place the composite material, the microwave generator sends microwaves into the microwave cavity for heating the composite material, and the electric heating element is also used for heating the composite material. The shielding element is located in the microwave cavity and is used to cover the outer surface of the composite material. The microwave partial shielding element is composed of a shielding microwave area and a microwave transmitting area. The microwave transmitting area includes one or more slits to make the microwave cavity The microwave energy enters the composite material from the gap and is absorbed by it; the vacuuming component includes a vacuum bag and a vacuum tube, and is used to extract the gas generated during the curing process of the composite material in time; The composite material provides vibrations with vibration frequencies below 5000Hz and vibration tables that can provide vibration accelerations above 2g.

In a specific embodiment, the vibrating table is a vibrating table capable of providing the composite material with vibration of a vibration frequency below 2000 Hz and a vibration of a vibration acceleration of more than 3 g.

In a specific embodiment, the vibrating table is a vibrating table capable of providing the composite material with vibration at a vibration frequency of 10 Hz or higher and vibration at a vibration acceleration below 50 g.

In a specific embodiment, the vibrating table is a vibrating table capable of providing the composite material with vibration with a vibration frequency of more than 20 Hz and vibration with a vibration acceleration of less than 30 g.

In a specific embodiment, the vibrating table is a vibrating table capable of providing the composite material with vibration of at least part of the vibration frequency in the range of 30-1000 Hz and vibration of at least part of the vibration acceleration in the range of 5-20 g.

In a specific embodiment, a plurality of vibrating hammers are connected below the vibrating table (7), and each vibrating hammer is connected with a hydraulic oil pipe or gas pipe (71) for vibration to be used together for the vibrating table and setting The composite material on the shaker table provides random uninterrupted vibration in the vertical direction of acceleration, preferably the vibratory hammers are evenly distributed under the shaker table.

In a specific embodiment, the device further includes a temperature measurement component, and the temperature measurement component includes a temperature measurement head (41), a data acquisition instrument (42) and a temperature measurement transmission line (43). The head is arranged in the composite material inside the microwave partial shielding member, one end of the temperature measurement transmission line is connected with the temperature measurement head, and the other end is led out to the outside of the microwave cavity to be connected with the data acquisition instrument, which is used to timely Displays the temperature measured by the thermometer.

In a specific embodiment, the area of the microwave-transmitting region accounts for less than 30% of the area of the entire microwave partial shielding member, preferably less than 15%, more preferably less than 5%; the length-to-width ratio of the slit is ≥2:1, preferably ≥5:1, more preferably ≥10:1; the length of the slit is ≥20mm, preferably ≥40mm, more preferably ≥80mm, and the width of the slit is 1-30mm.

In a specific embodiment, the power of the microwave generator is adjustable, preferably linearly adjustable, the microwave generator is located at the top of the microwave cavity, and the microwave generator includes a wave-transmitting temperature-resistant plate and a slit antenna.

In a specific embodiment, the vacuum bag is arranged on the outer side of the microwave partial shielding member, and an air felt (6) is also arranged between the vacuum bag and the microwave partial shielding member for the purpose of gas diffusion during vacuuming. To guide the flow, the vacuum evacuation component further includes a quick-connect joint (9) and a sealing tape (10).

Using the device and method provided by the present invention can at least bring the following beneficial effects:

1) The present invention provides a multi-field coupled composite energy field such as an electric thermal energy field, a microwave energy field and a vertical vibration acceleration field, so that the internal temperature field and curing degree of the composite material are uniform when heating and curing.

2) In the device provided by the present invention, the electric heating element is used as the main heating source to heat the composite material as a whole, and the microwave fixed-point or directional heating is used to provide energy as an auxiliary, so that the heating and curing of the composite material can be truly uniform everywhere. The invention can realize the uniform distribution of the internal temperature of the composite material part and the synchronization of the internal and external curing of the part, thereby greatly reducing the probability of various defects such as delamination, deformation, cracking, residual stress, etc. The scrap rate caused by the uneven internal temperature is greatly reduced, and the production quality and production efficiency of the product are improved.

3) The present invention truly realizes the uniform temperature field of thick composite materials and large-scale composite materials with variable thickness, and simultaneously solidifies inside and outside, which helps to solve the problem of co-manufacturing of large-scale composite material main bearing parts. The invention can be used for producing aerospace parts with strict quality requirements, and has important practical significance for improving the production quality of aerospace parts.

4) In a specific embodiment, the present invention combines the computer automatic control technology, and the composite energy field curing of the composite material can be automatically controlled by using the device provided by the present invention.

In general, the curing device and curing method of the present invention can enable the composite material prepreg to be cured under atmospheric pressure to obtain a product with excellent properties.

Description of drawings

FIG. 1 is a schematic structural diagram of the device of the present invention.

Among them, 1. Microwave generator, 2. Microwave cavity, 3. Partial microwave shielding member, 41. Temperature measuring head, 42. Data acquisition instrument, 43. Temperature measuring transmission line, 5. Vacuum bag, 6. Air felt, 7. Vibrating table, 71, hydraulic oil pipe or gas pipe for vibration, 8, vacuum pipe, 9, quick joint, 10, sealing tape, 222, electric heating element, 01, composite material.

Detailed ways

Embodiments of the invention are described in detail below, but the invention can be practiced in many different ways as defined and covered by the claims.

It is known to those skilled in the art that a shaking table is also called a vibration exciter or a vibration generator. It is a device that uses electric, electro-hydraulic, piezoelectric or other principles to obtain mechanical vibration. Achieve higher acceleration and higher operating frequency with a smaller table. The vibration test is mainly divided into sinusoidal vibration and random vibration. The vibrating table is suitable for conducting relevant vibration tests on samples in laboratories and production lines of automotive parts, electronic components, components, medicine, food, furniture, gifts, ceramics, packaging and other industries. Such as environmental acceptance test, quality appraisal test, reliability appraisal test, durability test, vibration simulation analysis, material property test, fatigue test, vibration prevention improvement, etc. Simulate the vibration environment experienced by products during manufacture, assembly, transportation and use to evaluate the vibration resistance, reliability and integrity of their structures.

That is to say, the current use of the vibration table is mostly limited to artificially accelerated testing of the life of the product.

In the present invention, the random vibration in the vertical direction generated by the vibrating table is used in the curing process of the resin-based carbon fiber composite material, so that the composite material prepreg is cured into a qualified composite material part. The curing principle in the present invention refers to the concrete vibration principle. Specifically, when the concrete is poured with a concrete mixer, the air bubbles in it must be removed, and the concrete must be tamped to make the concrete densely combined and eliminate the honeycomb pitted surface of the concrete, so as to improve its strength and ensure the quality of the concrete components. The above-mentioned process of eliminating air bubbles and tamping the concrete is concrete vibrating. The vibration frequency of the low-frequency type is 25-50HZ; the medium-frequency type is 83-133HZ; the high-frequency type is above 167HZ.

The difference between the present invention and the concrete vibrator is that firstly, the vibration frequency of the present invention is not limited to the frequency of the concrete vibrator, and secondly, the concrete vibrator belongs to cold curing, while the present invention belongs to the thermal curing process; in addition, in the present invention, more than 2g is used The vertical downward vibration of vibration acceleration, while the direction of vibration acceleration in concrete vibrating is generally disordered.

Referring to the secondary vibration of concrete about 1 to 4 hours before initial setting, the present invention can also test the effect of secondary vibration on thermal curing of the composite material in the follow-up.

The vibrating table in the present invention can use a now mature technology, such as a commercially available "accelerated life tester", the vibrating table itself is dedicated to the accelerated failure test of product life, and in the present invention, such a vibrating table is used for Instead of the high pressure in the autoclave, the curing effect of the carbon fiber resin composite material is better.

In addition, the direction of the gravitational acceleration g is always vertically downward. In the present invention, the vibration table can provide a vibration acceleration of more than 2g, that is, the vibration acceleration provided by the vibration table during the curing process is more than 2g, and g=9.8m/s ² , the vibration acceleration during curing is preferably 2 to 50 g, more preferably 5 to 30 g. That is, the vibration acceleration direction provided by the vibration table in the present invention is also the vertical direction.

Example 1

Use the device of the present invention to cure the T800 composite material,

Firstly, the composite material was vibrated by electric heating and vibrating table. The temperature was raised from room temperature to 80°C at 1.5°C/min, and then kept for 30min. s ² , the composite material is vacuumed during the vibration treatment, and the ambient pressure of the composite material is atmospheric pressure.

After the composite material was vibrated at 80 °C for 30 minutes, the vibration was stopped, and the temperature was directly raised from 80 °C to 180 °C for thermal curing. The heating rate is 3 to 5°C/min. At this stage, the composite material is continuously vacuumed, and the environmental pressure of the composite material is still atmospheric pressure. The temperature was raised to 180° C. and then kept for 150 minutes, and then the composite material was obtained after cooling in the furnace. Therefore, under vacuum conditions and ambient atmospheric pressure, the pressure of the composite material is 0.1-0.2Mpa.

The porosity of the obtained composite material article is 0.32-0.43%, and the interlaminar shear strength of the obtained composite material article is 94.65-98.96 Mpa.

In the device of the present invention, for example, the vibration environment of the vibrating table is: three-axis six-degree-of-freedom Gaussian random vibration, the maximum acceleration is 75g, the vibration frequency is 10～5000Hz, and the working temperature range is -100℃～+ 200°C. The vibration platform uses the external air compressor as the power source, and continuously uses the air hammer to provide a stable vibration source for the vibration table. During the vibration process, the vibration is transmitted from the vibration table to the composite material in the vertical direction.

Example 2

Use the device of the present invention to cure the T800 composite material,

Firstly, the composite material was vibrated by electric heating and vibrating table. The temperature was raised from room temperature to 135°C at 1.5°C/min, and then kept for 30min. The composite material is vacuumed, and the ambient pressure of the composite material is atmospheric pressure.

After the composite material was vibrated at 135 °C for 20 minutes, the vibration was stopped, and the temperature was directly raised from 135 °C to 180 °C for thermal curing. The heating rate is 3 to 5°C/min. At this stage, the composite material is continuously vacuumed, and the environmental pressure of the composite material is still atmospheric pressure. The temperature was raised to 180° C. and then kept for 150 minutes, and then the composite material was obtained after cooling in the furnace.

The porosity of the obtained composite material part is 0.23-0.28%, and the interlaminar shear strength of the obtained composite material part is 105.32-107.95 Mpa.

Example 3

Use the device of the present invention to cure the T800 composite material,

First, the composite material is heated and cured by electric heating and microwave heating in a composite thermal field, and the composite material is vibrated on a vibrating table at the same time. -2000Hz random vibration, the vibration acceleration is 10g, the composite material is vacuumized during the vibration treatment, and the environmental pressure of the composite material is atmospheric pressure.

After the composite material was vibrated at 180 °C for 10 min, the vibration was stopped, and the heat preservation at 180 °C was continued for 150 min. The composite thermal field of electric heating and microwave heating kept the composite material warm and solidified. At this stage, the composite material was continued to be vacuumized. The ambient pressure is still atmospheric. After the heat preservation is completed, the composite material part is obtained after cooling with the furnace.

The porosity of the obtained composite material part is 0.16-0.22%, and the interlaminar shear strength of the obtained composite material part is 109.74-116.33 Mpa.

Comparative Example 1

In this comparative example, the T800 composite material was cured at high temperature and high pressure by using an autoclave alone, and the curing pressure was 0.6MPa. Electric heating in the autoclave made the temperature of the composite material rise from room temperature to 180°C at 1.5°C/min, and the temperature was raised to 180°C. After 180 ℃, the temperature was kept for 150 minutes, and the composite material was obtained after cooling with the furnace. During the whole curing process, the composite material was subjected to vacuum treatment.

The porosity of the obtained composite material article was 0.36%, and the interlaminar shear strength of the obtained composite material article was 98.15 Mpa.

Comparative Example 2

This comparative example is to use microwave alone to perform high-temperature overall curing of T800 composite material. The curing pressure is ambient pressure, that is, atmospheric pressure. The microwave heating makes the temperature of the composite material increase from room temperature to 180 °C at a rate of 3-5 °C/min, and then heat up to 180 °C After holding for 150 minutes, the composite material is obtained after cooling with the furnace, and the composite material is vacuumized during the whole curing process.

The porosity of the obtained composite material part is 1.45-1.56%, and the interlaminar shear strength of the obtained composite material part is 74.63-76.97 Mpa.

From the comparison results of Examples 1 to 3 of the present invention and Comparative Examples 1 and 2, it can be seen that the properties of the composite parts obtained after curing by the device of the present invention are completely comparable to the standard curing process of autoclave curing. Even after the vibration duration, vibration end temperature, vibration frequency and vibration acceleration are optimized by the present invention, the composite material curing effect in the device and method provided by the present invention can be significantly better than that of autoclave curing. This enables the present invention to solve the problem of "I hope to no longer use expensive and unsafe autoclave equipment for composite material curing", and at the same time obtain an unexpected composite material curing effect, and the performance of the cured product is even excellent. Autoclave curing is the standard procedure.

To sum up, the present invention has at least the following features:

1. The present invention prepares composite material parts with excellent performance under the condition of vacuuming and no external pressure, which reduces the curing and molding pressure of composite materials, and accelerates the curing speed to a certain extent, saving equipment costs and curing costs, It realizes the safe, uniform, high-efficiency and energy-saving molding and curing of composite parts.

2. The present invention can also make the performance of the composite material better than the composite material produced by the standard procedure of autoclave curing by optimizing the vibration duration, the vibration end temperature, the vibration frequency and the vibration acceleration. Analysis of the reason may be that when the composite material is cured at a high pressure of 0.6MPa, although the pressure can effectively compact the prepreg layer of the composite material, thereby improving the quality of the part, the pressure gradually increases from the surface of the composite material to the surface of the composite material. The internal and external pressures are different, so the porosity of the cured product is relatively high and the pore distribution is uneven. In the present invention, under the downward vibration acceleration, the composite material is subjected to uniform vibration acceleration everywhere, which can also effectively compact the prepreg layer of the composite material, thereby improving the quality of the product and curing the obtained product. The porosity can be lower and the pore distribution more uniform.

3. In the present invention, the composite heating device and the vibration device are integrated, so that the composite material parts can continue to heat up or keep heat for thermal curing without cooling after the vibration and heating treatment, and the product performance of the solidified composite material parts is better. it is good.

4. In a specific embodiment, in the present invention, the area of the composite material that does not need special heating or curing is covered with microwave shielding material, and the area that needs special heating or curing is not covered with microwave shielding material. , leaving one or more gaps, so that the microwave partial shielding element consists of a microwave shielding area and a microwave transmitting area. The microwave generator generates microwaves into and uniformly dispersed in the microwave cavity, and heats or solidifies the inside of the area of the composite material without the microwave shielding material (transmitting the microwave area). Since microwaves cannot enter the areas where the microwave shielding material is attached (the microwave shielding area) on the composite material product, these areas cannot absorb microwave energy, but can only receive the overall heating from the electric heating element 222 . Therefore, by means of microwave fixed-point heating and integral heating of the electric heating element, the temperature of the composite material article of the present invention can be uniform throughout the curing process. Therefore, the composite energy field heating provided by the present invention enables microwaves to specifically heat and solidify the parts of the composite material workpiece. The overall heating of the workpiece can make the heating and curing process uniform and controllable as a whole, so as to obtain high-performance products. Or in the present invention, before the composite material is heated and solidified, a layer of strong wave absorbing material is arranged on a part of the outer surface of the composite material to enhance microwave energy absorption at a part of the upper part of the composite material. It can also play the effect of microwave fixed-point heating and overall heating of the electric heating element.

In addition, the present invention is an improvement and innovation based on a series of patents or patent applications CN201610025303, CN201610027791, CN201610027866, CN201610030557 and CN201710214268. If there are any points in the present invention that are not described in detail, you can refer to these patents or patent applications for implementation. . That is, the present invention also incorporates the contents contained in these patents or patent applications.

The shape of the incubator can be any shape such as a cube and a cylinder. In the prior art, the autoclave used for curing T800 prepreg needs to withstand pressure, and the tank wall is thick. However, the incubator in the present invention only needs to provide an atmospheric pressure or a pressure slightly higher than the atmospheric pressure, so its cost is much lower. Preferably, in the present invention, a fan for convection of hot air is provided in an incubator other than the microwave cavity. The vibrating table is connected to the bottom plate of the microwave cavity by using more than three coil springs, preferably at least one spring is provided at each of the four corners below the table surface of the vibrating table to support the vibrating table.

The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it cannot be considered that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field to which the present invention pertains, without departing from the concept of the present invention, some simple deductions and substitutions can also be made, all of which should be regarded as belonging to the protection scope of the present invention.

Claims (10)

1. a kind of composite material microwave curing apparatus, including electrothermal piece (222), shake table (7), microwave generator (1), microwave Chamber (2), microwave shadow shield part (3) and vacuumizing part, the electrothermal piece (222) and shake table (7) are arranged at microwave cavity (2) in；For placing composite material (01) on shake table, the microwave generator sends microwave into microwave cavity for being described Composite material heat supply, the electrothermal piece (222) are also used for as the composite material heat supply, and the microwave shadow shield part is located at micro- Wave is intracavitary and is used to be covered on the outer surface of composite material, and the microwave shadow shield part (3) is by shield microwaves area and through micro- Wave district's groups are at described to make the microwave energy in microwave cavity from gap into compound comprising one or more gap through microwave region It is absorbed in material；The vacuumizing part includes vacuum bag (5) and vacuum tube (8), and for solidifying composite material The gas generated in the process is extracted out in time；The shake table is can provide 5000Hz or less vibration frequency to the composite material Vibration and can provide 2g or more vibration acceleration vibration shake table.

2. the apparatus according to claim 1, which is characterized in that the composite material is T800 carbon-fibre reinforced epoxy resin Prepreg, the shake table for the vibration of 2000Hz or less vibration frequency can be provided to the composite material and can provide 3g with The shake table of the vibration of upper vibration acceleration.

3. device according to claim 1 or 2, which is characterized in that the shake table is can provide to the composite material The vibration of 10Hz or more vibration frequency and can provide 50g or less vibration acceleration vibration shake table.

4. device according to claim 3, which is characterized in that the shake table is can provide 20Hz to the composite material The vibration of the above vibration frequency and can provide 30g or less vibration acceleration vibration shake table.

5. device described according to claim 1~any one of 4, which is characterized in that the shake table is can be to described multiple Condensation material at least partly vibration of vibration frequency is provided in 30~1000Hz and can provide in 5~20g at least partly vibration plus The shake table of the vibration of speed.

6. device described according to claim 1~any one of 5, which is characterized in that be connected with below the shake table (7) Multiple vibration hammers, and each vibration hammer is connect with vibration hydraulic oil pipe or tracheae (71) to be provided commonly for as shake table and set The composite material set on a vibration table provides the random continual vibration of acceleration vertical direction, and the preferably described vibration hammer is uniform It is distributed in below shake table.

7. device described according to claim 1~any one of 6, which is characterized in that described device further includes temperature-measuring part, And the temperature-measuring part includes temperature measuring head (41), data collecting instrument (42) and thermometric transmission line (43), the temperature measuring head setting exists In composite material on the inside of microwave shadow shield part, thermometric transmission line one end is connect with temperature measuring head, and the other end leads to institute It states and is connect on the outside of microwave cavity with the data collecting instrument, the data collecting instrument for showing the temperature that the temperature measuring head measures in time Degree.

8. device described according to claim 1~any one of 7, which is characterized in that the area through microwave region accounts for The 30% of entire microwave shadow shield part area is hereinafter, it is preferred that 15% hereinafter, more preferably below 5%；The length in the gap Width is than being >=2:1, preferably >=5:1, more preferably >=10:1；The length in the gap be >=20mm, preferably >=40mm, more preferably >= 80mm, and the width in gap is 1~30mm.

9. device described according to claim 1~any one of 8, which is characterized in that the power of the microwave generator can It adjusts, preferably its power linear is adjustable, and microwave generator is located at the top of microwave cavity, and the microwave generator includes wave transparent heat-resistant board And leaky antenna.

10. device described according to claim 1~any one of 9, which is characterized in that the vacuum bag is arranged in microwave office The outside of portion's shielding part, and airfelt (6) are additionally provided with for vacuumizing between the vacuum bag and microwave shadow shield part When gas water conservancy diversion, the vacuumizing part further includes quick union (9) and sealant tape (10).